sexta-feira, 26 de agosto de 2011

SPORT: ESTUDO MILIONÁRIO PATROCINADO PELO GOVERNO AMERICANO DEFINE CORRETAMENTE AS INDICAÇÕES CIRÚRGICAS E NÃO-CIRÚRGICAS NAS TRÊS PRINCIPAIS DOENÇAS DA COLUNA VERTEBRAL

What is SPORT?

The Spine Patient Outcomes Research Trial is a 5-year study that looked at 3 of the most common back conditions and compared surgical and non-surgical treatments. Approximately 2500 patients took part in the study, which was conducted at 13 sites across the country.

What are the conditions SPORT studied?

Intervertebral disc herniation, commonly known as a slipped or ruptured disc. A herniated disc is a painful back condition that occurs when some of the disc material in the backbone pops out of place and bulges into the spinal canal, creating pressure on the spinal cord and pain that typically goes all the way down the leg. It is also known as a herniated lumbar or ruptured disc.


Spinal Stenosis. The spinal canal runs through the vertebrae and contains the nerves supplying sensation and strength to the legs. Between the vertebrae are the intervertebral discs and the spinal facet joints. As people age, there can be a drying out and shrinking of the disc spaces between the bones (80% of the disc is made up of water). You can feel pain anywhere along your back or leg when the nerve is pressed in this way.

Degenerative spondylolisthesis (spon-duh-low-lis-thee-sis) is a condition in which a vertebra in the spine slips forward out of alignment. It is caused by degeneration of both the disc and the facet joint, which allows the vertebra to move out of place.


Why is SPORT important?

Low back pain is one of the most widely experienced health problems in the world. Eight out of ten people will have back pain at some point in their lives. Next to the common cold, it is the main reason for missed work days and physician visits. It is estimated that the costs of low back pain range between $30 and $70 billion every year.

And yet, there is no clinical "proof" that surgery - one of the most common treatments for back pain - is effective. In this case, "proof" means no evidence through a standard clinical trial that compares one treatment to another. Certainly some patients have conditions that clearly call for surgery and they experience immediate relief from a painful and debilitating condition. But other cases are less clear-cut. It may be that alternatives to surgery, such as physical therapy, over-the-counter medication, or other non-invasive therapies would be just as effective.

So this trial asked the question: Is surgery BETTER than non-surgical therapy for patients with the three conditions described above?

How was the research conducted?

Clinical trials look at the safety or effectiveness of a medication or treatment. Typically, patients are "randomized", meaning that those who agree to take part in a trial also agree that they will be randomly selected to receive the treatment or not. This is often done by giving one group of patients the actual drug or treatment, while the other group receives a placebo. Trial participants generally do not know which treatment they are receiving. This is called a "blinded" study.

In the case of back surgery, of course, there is no way to "blind" the patients. So, after watching a Shared Decision-Making video that described what we know about back surgery vs. non-surgery, one group of patients in this trial agreed to be randomly selected for surgical or non-surgical treatment.
Another group, called the "observational cohort", chose not to participate in the randomized trial and to make their own decision about what approach to pursue. However, they did agree to take part in the rest of the trial, that is, to be surveyed initially and participate in follow-up evaluations during the next 12 to 48 months.

How were the trial participants selected?

There are very strict criteria for enrolling a patient in a research trial. Before a trial is started, it and its methods must be approved by the sponsoring organization - in this case the National Institutes for Health - and by an Internal Review Board (IRB), made up of health care professionals and others not affiliated with the trial itself. Finally, a data safety monitoring board oversees the trial, constantly reviewing the results and information being gathered. This board can step in and stop a trial at any time if it appears the treatment isn't helping the patients involved.

In this trial, people in each of the categories being looked at had to meet very specific criteria before being considered eligible for the study. They had to have a common set of symptoms and diagnosis to make sure the comparisons would be accurate. They also could not have any symptoms or conditions that might cause the trial to be harmful to their health. They could not be in obvious, immediate need of surgery. A full list of the criteria, as well as a detailed discussion of the methodology, is available in a paper called "Design of SPORT". This paper also lists the kinds of non-surgical therapies studied.

Who did the study?

The participating institutions were:
  • William Beaumont Hospital, Royal Oak, MI
  • Dartmouth-Hitchcock Medical Center, Lebanon, NH
  • Emory University, Decatur, GA
  • New York University/Hospital for Joint Diseases, New York, NY
  • Hospital for Special Surgery, New York, NY
  • Kaiser Permanente, Oakland, CA
  • Nebraska Foundation for Spinal Research, Omaha, NE
  • Rothman Institute at Thomas Jefferson Hospital, Philadelphia, PA
  • Rush- Presbyterian-St. Luke's Medical Center, Chicago, IL
  • University of California at San Francisco, San Francisco, CA
  • University Hospitals of Cleveland/Case Western Reserve University, Cleveland, OH
  • Washington University, St. Louis, MO
  • Maine Spine and Rehabilitation, Scarborough, ME

What are the SPORT results?

The results of SPORT were released in three phases, in the order of the three conditions studied:
  1. Intervertebral disc herniation, published in JAMA, November, 2006
  2. Degenerative Spondylolisthesis, published in The New England Journal of Medicine, May, 2007
  3. Spinal Stenosis, published in The New England Journal of Medicine, February 21, 2008
The first results were from the Intervertebral Disc Herniation trial. Full papers can be accessed here, but in summary, the study found that while both groups improved substantially after treatment, the improvement from standard surgery, a procedure called "disectomy", was more rapid. Patients who had surgery also reported better results in physical function and satisfaction one and two years after the operation.

The second results are from the trial for Degenerative Spondylolisthesis. The full paper can be accessed here. In summary, the study found that patients with spinal stenosis accompanied by degenerative spondylolisthesis who were treated surgically showed substantially greater improvement in pain and function through 2 years follow-up compared to patients treated nonsurgically. Because patients in the randomized cohort "crossed over" either from the non-operative arm to have surgery or from the surgery arm to remain non-operative, the analyses were non-randomized, as-treated comparisons with careful control for potentially confounding baseline factors.

The third results are from the trial for Spinal Stenosis. The full paper can be accessed here. In summary, the study found that patients with spinal stenosis who were treated surgically showed significantly greater improvement in pain, function and disability through 2 years follow-up compared to patients treated nonsurgically. Because patients in the randomized cohort "crossed over" either from the non-operative arm to have surgery or from the surgery arm to remain non-operative, the analyses were non-randomized, as-treated comparisons with careful control for potentially confounding baseline factors.

Analyses of the 4-year follow-up data for each of the three cohorts, Intervertebral Disc Herniation, Spinal Stenosis, and Degenerative Spondylolisthesis, demonstrated that the gains the surgical patients had made were maintained at four years.

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